Problems with multicast

I want to use multicast in a daemon to exchange messages between daemon runnning on different lede routers.

So I wanted to test if multicast is working. I installed igmpproxy and followed the wiki insructions.

I started a server with

 iperf -s -u -B -i 1

and a client

iperf -c -u -T 32 -t 3 -i 1

Nothing happens. But after starting parallel the same server on my laptop it's working.
But I'm not able to send messages between my laptop and my lede router.

laptop <-> laptop
lede <-> lede (with server running parallel on laptop)

Any ideas?

I had no luck with igmproxy either. smcroute works much better for me.
Igmpproxy overwrites the source address and smcroute does not.
So imgpproxy is only useful for multicast like tv steam from your isp or something like that.
smcroute can do "real" multicast routing.
But im not sure :expressionless: So if im wrong someone correct me please.
Did you try to increase the the ttl of multicasts? Multicast normaly only last 1 hop.
Something like:
iptables -t mangle -A PREROUTING -i $interface -d -j TTL --ttl-inc 1
Can you also give more details about your setup please?

My Setup for now...:

I can't find any information about smcroute. Are there some tutorials?

The command syntax is not right... ^^

iptables -t mangle -A PREROUTING -i $interface -d -j TTL --ttl-inc 1

Special is this first line:

[ 3] local port 5001 connected with port 55463
[ ID] Interval Transfer Bandwidth Jitter Lost/Total Datagrams
[ 3] 0.0- 1.0 sec 129 KBytes 1.06 Mbits/sec 0.009 ms 0/ 90 (0%)
[ 3] 0.0- 1.5 sec 197 KBytes 1.05 Mbits/sec 0.005 ms 0/ 137 (0%) is the wan port of my acer c7... So somehow my muticast goes from to my wan network and then to the router? Something is wrong...

You have to replace $interface with a interface name like eth0.
You need a rule for each interface that should forward multicast traffic.

But what do you want to achieve exactly? Why do you want to route multicast traffic between the 2 routers?
Also how are the routers connected?
Are both routers running lede/openwrt?
Is the c7 connected through its wan port to one of fritzbox's lan port or vice versa?
If Yes you also need to create some firewall rules.

For smcroute check this page:

For example on your c7:
I dont know the exact interface names for this device. So you have to replace them accordingly.
Lets assume eth0 is wan your interface and eth1 is your lan interface.


phyint eth0 enable
phyint eth1 enable

mgroup from eth0 group
mgroup from eth1 group

mroute from eth0 group to eth1
mroute from eth1 group to eth0

Then create the following custom firewall rules:
iptables -t mangle -A PREROUTING -i eth1 -d -j TTL --ttl-inc 1
iptables -t mangle -A PREROUTING -i eth0 -d -j TTL --ttl-inc 1

And allow incoming multicast traffic on the wan port.

Then do the same on the fritzbox.